KR100705249B1 - Leadframe for manufacturing semiconductor package - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame for manufacturing a semiconductor package. In the past, in a singulation process after a molding process, a molding resin surface which is cut together with a tie bar at a corner thereof is cut by the cutting means, and thus defects in the semiconductor package are caused by tearing or short circuit. To solve this problem, during the singulation process of the semiconductor package, first cut the tie bar and the molding surface along the corner singulation line, and then cut the second along the singulation lines of the X and Y axes. The present invention is to provide a lead frame for manufacturing a semiconductor package having a structure to prevent the cutting means from contacting the first cut molding resin surface, thereby preventing the corner molding resin surface from falling off and collecting.

Lead frame, extension, singulation, cutting means, lead, inner lead, outer lead

Description

Leadframe for semiconductor package manufacturing             

1 is a bottom view showing an embodiment of a lead frame for manufacturing a semiconductor package according to the present invention;

2A and 2B are plan and bottom views illustrating a process of singulating a semiconductor package manufactured using the lead frame of FIG. 1;

3A and 3B are perspective views illustrating a state in which a singulation process is completed in manufacturing a semiconductor package using the lead frame of FIG. 1;

Figure 4 is a bottom view showing another embodiment of a lead frame for manufacturing a semiconductor package according to the present invention,

5A and 5B are plan and bottom views illustrating a singulation process of a semiconductor package manufactured using the lead frame of FIG. 3;

6A and 6B are perspective views illustrating a state in which a singulation process is completed in manufacturing a semiconductor package using the lead frame of FIG. 4;

7 is a bottom view showing a conventional lead frame structure,

8A and 8B are plan and bottom views illustrating a process of singulating a semiconductor package manufactured using a conventional lead frame;

9A and 9B are perspective views showing a conventional semiconductor package after a singulation process.

<Explanation of symbols for the main parts of the drawings>

10: lead frame 12: lead

14: inside lead 16: outside lead

18: extension 20: tie bar

22: chip mounting plate 24: side rail

26: dam bar 28: resin

30: cutting means T: upper molding line

P: semiconductor package line and singulation line

HE: Half Etching

The present invention relates to a lead frame for manufacturing a semiconductor package, and more particularly, to improve a structure of a lead adjacent to a tie bar of a lead frame, thereby preventing a damage to a corner molding resin surface by a cutting means during a singulation process. The present invention relates to a lead frame for manufacturing a package.                         

In general, a lead frame for manufacturing a semiconductor package is manufactured in various forms by varying a width and a thickness and a length, an area of a semiconductor package region, a lead length, and an area of a chip mounting plate.

Among the lead frames manufactured as described above, the so-called micro lead frames are manufactured so that the semiconductor package region is arranged in a matrix arrangement of 3x4, 4x4, 4x5, etc. according to an arbitrary design. Briefly described with reference to Figure 7 attached the structure as follows.

The lead frame 10 includes a side rail 24 having a large outer frame, a chip mounting plate 22 on which semiconductor chips are mounted, and four corners of the chip mounting plate 22, and the side rails 24. The tie bars 20 which hold the chip mounting plate 22 while integrally connecting the internal parts are integrally formed on each inner surface of the side rail 24 and the ends thereof are formed on all sides of the chip mounting plate 22. It consists of a plurality of leads 12 which are located adjacent to each other, and a dam bar 26 that connects the leads 12 and prevents shaking of the leads and blocks external flow of the resin during molding.

In FIG. 7, reference numeral “T” denotes an upper molding line and “P” denotes a semiconductor package region line, and the structure of the lead is further described in detail based on the semiconductor package region line P. FIG. Is as follows.

The outer portion integrally connected to the side rails 24 with respect to the semiconductor package region line P is the outer lead 16, and the inner portion is the inner lead 14, and the inner bottom of the inner lead 14 is formed. Is processed by half etching (HE).

In addition, the bottom surface, which is not half-etched, of the inner lead 14 is a land surface exposed to the outside after the semiconductor package molding process, and the inner lead 14 between the upper molding line T and the semiconductor package region line P is formed. The upper surface is also a land surface exposed to the outside.

Herein, the structure of the chip mounting plate and the tie bar will be described in more detail.

The bottom edges of the chip mounting plate 22 are half-etched (HE), and the center bottom is not half-etched, and thus exposed to the outside after the molding process, thereby dissipating heat generated in the semiconductor chip. .

In addition, the bottom of the tie bar 20 is half-etched (HE) as long as the length from the upper molding line (T) to the chip mounting plate 22, the upper molding line (T) and the semiconductor package region line ( The bottom between P) is not half-etched and exposed to the outside after the molding process.

Here, a process of manufacturing a semiconductor package using a conventional lead frame having the above structure will be described below in order.

First, a process of attaching a semiconductor chip to the chip mounting plate 22 of the lead frame 10, a process of bonding a bond between the bond finger of the inner lead 14 and the bonding pad of the semiconductor chip with a wire, and the semiconductor chip And molding the resin 28 to protect the wire and the inner lead 14 from the outside, and singulating the outer lead 16 along the semiconductor package region line P. A semiconductor package 100 having a structure as shown in Figs. 9A and 9B is manufactured.

In the molding step, when the resin 28 is filled into the dam bar 26 as shown in FIGS. 8A and 8B, the bottom of the chip mounting plate 22 and the inner lead that are not half-etched. The bottom surface of 14 is exposed to the outside, and the resin 28 filled between the upper molding line T and the semiconductor package region line P is filled only in the space between the respective inner leads 14.

Accordingly, as described above, the bottom surface, which is not half-etched, of the inner lead 14 is exposed to the outside as a land for input / output terminals, and the inner lead 14 between the upper molding line T and the semiconductor package region line P is exposed. The upper surface is also a land surface exposed to the outside.

In this case, the semiconductor package region line P becomes a singulation line.

Herein, the singulation process performed after the molding process and the problems thereof will be described in detail with reference to FIGS. 8A and 8B.

In the process of singulating into a single semiconductor package using the cutting means 30 along the singulation line, as shown in FIGS. 8A and 8B, first, a tie along the corner side singulation line P is used. First cutting the bar 20 and the peripheral molding resin 28 surface of the tie bar 20, and then the outer lead 16 and the outer lead along the singulation line P of the X and Y axes By secondly cutting the surface of the molding resin 28 between (16), it is singulated into the semiconductor package 100 shown in FIGS. 9A and 9B.

At this time, the corner line of the singulation line (P) and the X-axis or Y-axis line is singulated while forming an obtuse angle with each other, the molding resin 28 surface of the obtuse portion is formed on the cutting means (30) Thereby, the problem is that the overlapped cutting, tearing or short circuit.

More specifically, the first cutting of the tie bar and the molding surface around the corner along the corner side singulation line, and then the plurality of external leads and the molding surface around the X-axis and Y-axis along the singulation line When the second cut is performed, both ends of the molding resin surface cut during the first cutting are broken or dropped due to the impact of the double cut during the second cutting, resulting in a defect of the semiconductor package.

Another reason for causing such a problem is that the corner portion of the semiconductor package is a state in which the tie bars of the lead frame and the molding resin are coupled to each other by an artificial force, and thus the distance between the tie bars and the molding resin is long because the distance between the tie bars and the adjacent leads is far. This occurs because the bonding force is a weak structure.

That is, the structural resin is weaker than the side portion of the package in which a plurality of leads and molding resins adjacent to each other are coupled to each other, so that the molding resin combined with the tie bar is easily separated from external shocks such as singulation means.

Therefore, in order to solve the above problems, the present invention, during the singulation process of the semiconductor package, after first cutting the tie bar and the molding resin along the corner side singulation line, along the singulation lines of the X-axis and Y-axis It is an object of the present invention to provide a lead frame for manufacturing a semiconductor package having a structure that prevents the cutting means from contacting the first cut molding resin surface to prevent the dropping and collection of the corner molding resin surface.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The present invention for achieving the above object: a side rail forming an outer skeleton, a chip mounting plate on which a semiconductor chip is mounted, and each corner of the chip mounting plate and the side rails integrally connected to hold a chip mounting plate In the lead frame for manufacturing a semiconductor package comprising a tie bar and a plurality of leads integrally formed on each inner surface of the side rail and positioned adjacent to four sides of the chip mounting plate,
It provides a lead frame for manufacturing a semiconductor package, characterized in that the extension portion is formed integrally extending to the tie bar on one side of each lead immediately adjacent to both sides of the tie bar so as not to touch the tie bar.

delete

In particular, the extension portion is characterized in that it is formed so that the corner line of the singulation line and the X-axis or Y-axis line includes an obtuse angle.

In a preferred embodiment, the bottom of the extension is half etched.

Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a bottom view illustrating an embodiment of a lead frame for manufacturing a semiconductor package according to the present invention, and FIGS. 2A and 2B are plan and bottom views illustrating a singulation process of a semiconductor package manufactured using the lead frame of FIG. 1. It is also.

Although the lead frame 10 has a strip structure in which semiconductor package regions in an array of 4 × 4 and the like are continuously arranged in one direction again, only one semiconductor package region is illustrated in FIG. 1.                     

As shown in FIG. 1, each of the semiconductor package regions includes a side rail 24 that forms a skeleton, a chip mounting plate 22 on which semiconductor chips are mounted, and each corner and the side of the chip mounting plate 22. The tie bar 20 holding the chip mounting plate 22 while integrally connecting the rails 24 and the inner side of each of the side rails 24 are integrally formed so that the end thereof is the chip mounting plate 22. It is composed of a plurality of leads 12 positioned adjacent to all four sides of the.

Particularly, as shown in FIG. 1, the lead 12 has an outer lead 16 that is integrally connected to the side rail 24 toward the side of the semiconductor package region line P. The part is an inner lead 14, and the inner bottom surface of this inner lead 14 is processed by half etching (HE).

In addition, the bottom edge of the four-sided edge of the chip mounting plate 22 is half-etched, and the tie bar 20 is half-etched by the length from the upper molding line T to the chip mounting plate 22. have.

Here, the extension part 18 which increases the area toward the tie bar 20 is integrally formed on one surface of the lead 12 adjacent to the tie bar 20, but the shape of the extension part 18 is limited. 1 and 2, the corner line of the singulation line P and the X-axis and Y-axis lines may be formed at an obtuse angle to each other.
That is, the extension portion 18 is formed to extend in a structure in which the area is increased toward the tie bar 20, the point where the corner line of the singulation line (P) and the X-axis and Y-axis line meet at an obtuse angle with each other It is formed in a shape extending to.

Here, the semiconductor package manufacturing process will be described using the lead frame of the present invention having the structure as described above, with reference to the molding process and the singulation process as follows.                     

Attaching a semiconductor chip to the chip mounting plate 22, bonding a bonding pad of the semiconductor chip to a bond finger of the inner lead with a wire, the semiconductor chip, the wire, and the chip mounting plate 22 When the molding process is performed, as shown in FIG. 2A, the resin 28 is filled into the dam bar 26, and at this time, the bottom of the chip mounting plate 22 and the inner lead that are not half-etched. The bottom surface of 14 is exposed to the outside, and the resin 28 filled between the upper molding line T and the semiconductor package region line P is filled only in the space between the respective inner leads 14.

Accordingly, as described above, the bottom surface, which is not half-etched, of the inner lead 14 is exposed to the outside as a land for input / output terminals, and the inner lead 14 between the upper molding line T and the semiconductor package region line P is exposed. The top view also shows a land surface exposed to the outside as shown in Fig. 2B.

In particular, the upper and lower surfaces of the extension portion 18 of the lead 12 are also exposed to the outside.

At this time, the semiconductor package region line P is the same line as the singulation line P sawing into individual semiconductor packages.

Next, the singulation is performed by using the cutting means 30 along the singulation line P. The cutting means 30 firstly follows the line on the corner of the singulation line P. A second cut is made along the singulation lines of the X and Y axes.

As a result, the tie bar 20 on the corner side during the first cutting, the molding resin 28 surface on both sides of the tie bar 20, and the extension of the lid 12 adjacent to the tie bar 20. A portion of the portion 18 is cut first, and a plurality of outer leads 16 and the remaining portions of the first cut extension 18 are cut at the time of the second cutting, as shown in FIGS. 3A and 3B. Singulation is achieved with the semiconductor package 100 having a structure.

That is, since the extension part 18 of the lead 12 includes a point where the corner line of the singulation line and the line of the X and Y axes form an obtuse angle, the extension part 18 of the lead is first cut. The cut is divided into and secondary cutting.

Accordingly, even if only the first cutting is performed along the corner side line of the singulation line P, since the molding resin 28 surface of the corner side is cut at once, it is conventionally cut twice over the second. Accordingly, the molding resin 28 may be prevented from being shorted or torn off.

Herein, another embodiment of the present invention will be described with reference to FIGS. 4 and 5A and 5B.

In another embodiment, the extension 18 of the lid 12 is characterized in that its bottom surface is half-etched as shown in FIG.

Accordingly, when the molding process is finished, the bottom surface of the extended portion 18 of the half-etched lead 12 is molded with the resin 28 and is not exposed to the outside as shown in FIG. 5B. The upper surface of the extension 18 is exposed to the outside as shown in FIG. 5A.

Next, a process of singulating with the cutting means 30 along the singulation line P is performed. The surface of the resin 28 molded on one side of the semiconductor package is called a dead bug. It is settled face down to perform the singulation process.

That is, the bottom surface of the extension portion 18 of the lead 12 half-etched and molded with resin is directed toward the top surface, and the top surface of the extension portion 18 of the lead 12 exposed to the outside due to half etching is not directed to the bottom surface. It is settled and then singulated.

Accordingly, when the first cutting is performed along the corner line of the singulation line P, the tie bar 20, the molding resin 28 surface around the tie bar 20, and the lead 12 are cut. A part of the extension part 18 of the () and the surface of the resin 28 molding the half-etched surface of the extension part 18 are cut.

Next, when the secondary cutting along the X-axis and Y-axis line of the singulation line P, the plurality of external leads 16 and the extension portion 18 of the primary cut lead 12 The remaining portion and the remaining surface of the resin 28 molding the half-etched surface of the extension portion 18 are cut, and singulated with a semiconductor package 100 having a structure as shown in FIGS. 6A and 6B. Will be migrated.

At this time, during the singulation process, since the extension part 18 of the lead 12 exposed to the outside is seated toward the bottom surface, the molding resin 28 adjacent to the tie bar 20 and the extension part ( The resin 28 molded on the half-etched surface of 18) is supported from below by the extension portion 18, so that the particles of the molding resin 28 do not easily fall off from the cutting surface.

On the other hand, after the singulation process, the bottom surface of the semiconductor package 100 can be seen from the bottom surface not etched half of the chip mounting plate 22, the bottom surface not etched half of the inner lead 14, and the tie bar ( Since the bottom surface not etched in 20) is exposed to the outside as in the structure currently manufactured, it is not necessary to change the mounting design for the motherboard separately.

As described above, according to the lead frame for manufacturing a semiconductor package according to the present invention, by forming an extension part extending toward the tie bar on one surface of the lead adjacent to the tie bar, the singular side regulation is performed during the singulation process of the semiconductor package. After the first cutting of the tie bar and molding surface along the line, and the second cutting along the X- and Y-axis singulation lines, the cutting means does not touch the first-cut molding surface again. Absorption can be prevented, resulting in an advantage of preventing a semiconductor package failure.

Claims (3)

A side rail forming an outer skeleton, a chip mounting plate on which semiconductor chips are mounted, a tie bar integrally connected to each corner of the chip mounting plate and the side rails to hold the chip mounting plate, and each inner surface of the side rail. In the lead frame for manufacturing a semiconductor package consisting of a plurality of leads formed integrally with and positioned adjacent to the four sides of the chip mounting plate, The extension part 18 which extends toward the tie bar 20 on one side of each of the leads 12 immediately adjacent to both sides of the tie bar, but not to touch the tie bar 20, is integrally formed. A lead frame for manufacturing a semiconductor package, characterized in that. The lead frame for manufacturing a semiconductor package according to claim 1, wherein the extension part (18) is formed to include an obtuse angle between a corner line of the singulation line (P) and an X-axis or Y-axis line. The lead frame according to claim 1 or 2, wherein the bottom surface of the extension portion (18) is half-etched.

Images